Choke coil for suppressing common-mode noise and normal-mode noise

Abstract

A choke coil exhibits sufficient capability in suppressing both common-mode noise and normal-mode noise while inhibiting an occurrence of magnetic saturation of a magnetic core. A terminal stand is formed of a frame and a magnetic plate. A split-type bobbin has a bobbin member made from a magnetic substance and a bobbin member made from an insulating substance. The bobbin is formed of a rod and three flanges provided for the rod. A pair of windings are reeled around the rod of the bobbin. Further, one side of an integral-type magnetic core formed in a hollow-rectangular shape is inserted into a hole formed in the rod of the bobbin. The magnetic bobbin member is placed outside a region surrounded by a closed magnetic path formed by the magnetic core. The magnetic bobbin member also forms a closed magnetic path together with the magnetic plate of the terminal stand.

What is claimed is: 
     
       1. A choke coil comprising: a pair of windings;   a split-type bobbin formed of an insulating member and a magnetic member and having a cylindrical rod around which said pair of windings are reeled and at least one flange extending from said cylindrical rod;   an integral-type magnetic core having a side which is inserted into a hole formed in said cylindrical rod, and forming a closed magnetic path; and   a terminal stand for supporting said split-type bobbin and forming a closed magnetic path together with the magnetic member of said split-type bobbin, wherein the magnetic member of said split-type bobbin is disposed outside a region surrounded by the closed magnetic path formed by said magnetic core.